创建HibernateUtil工具类以及在MySQL数据库中建立表

一 创建HibernateUtil

package com.cakin.util;

 

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.boot.registry.StandardServiceRegistry;

import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

import org.hibernate.cfg.Configuration;

 

public class HibernateUtil {

        private static SessionFactory sessionFactory;

        private static Session session;

 

        static {

                // 创建Configuration对象，读取hibernate.cfg.xml文件，完成初始化

                Configuration config = new Configuration().configure();

                StandardServiceRegistryBuilder ssrb = new StandardServiceRegistryBuilder()

                                .applySettings(config.getProperties());

                StandardServiceRegistry ssr=ssrb.build();

                sessionFactory=config.buildSessionFactory(ssr);

        }

        

        //获取SessionFactory

        public static SessionFactory getSessionFactory(){

                return sessionFactory;

        }

        

        //获取Session

        public static Session getSession(){

                session=sessionFactory.openSession();

                return session;

        }

        

        //关闭Session

        public static void closeSession(Session session){

                if(session!=null){

                        session.close();

                }

        }

}

 

二 在数据库中建立表

create table grade

(

    gid int primary key,

    gname varchar(20) not null,

    gdesc varchar(50)

);

create table student

(

    sid int primary key,

    sname varchar(20) not null,

    sex char(2),

    gid int

);

alter table student add constraint fk_student_gid foreign key (gid)

 

references grade(gid);